I just recently dropped my Torch onto our hardwood floor and the battery fell out. After it rebooted, it was quite less laggy and slow than before. I guess a battery pull once a week keeps your phone healthy? lol
I don't get much in the way of lags on my phone. But I do get to a point when I get a 2 to 3 second stall when closing an app - the screen will freeze up for that long during mid fade-out.
Reboot, battery pull or QuickPull... No help. The only time I get a smooth app close is for the first day or two after an OS install. Otherwise, everything else seems to run pretty smooth.